Aharonov-Bohm and Altshuler-Aronov-Spivak oscillations in the quasiballistic regime in phase-pure GaAs/InAs core/shell nanowires

Abstract

The realization of various qubit systems based on high-quality hybrid superconducting quantum devices is often achieved using semiconductor nanowires. For such hybrid devices, a good coupling between the superconductor and the conducting states in the semiconductor wire is crucial. GaAs/InAs core/shell nanowires with an insulating core and a conductive InAs shell fulfill this requirement, since the electronic states are strongly confined near the surface. However, maintaining a good crystal quality in the conducting shell is a challenge for this type of nanowire. In this work, we present phase-pure zinc-blende GaAs/InAs core/shell nanowires and analyze their low-temperature magnetotransport properties. We observe pronounced magnetic flux quantum periodic oscillations, which can be attributed to a combination of Aharonov-Bohm and Altshuler-Aronov-Spivak oscillations. From the gate and temperature dependence of the conductance oscillations, as well as from supporting theoretical transport calculations, we conclude that the conducting states in the shell are in the quasiballistic transport regime, with few scattering centers, but nevertheless leading to an Altshuler-Aronov-Spivak correction that dominates at small magnetic field strengths. Our results demonstrate that phase-pure zinc-blende GaAs/InAs core/shell nanowires represent a very promising alternative semiconductor-nanowire-based platform for hybrid quantum devices.